The Latest: 3 People Are In Critical Condition After Blast

The Latest on the oil rig explosion near New Orleans (all times local):

9:25 a.m.

A Louisiana sheriff says three people remain in critical condition, with two of them in a burn unit after an explosion at an energy plant on a lake near New Orleans.

At a Monday morning news conference, Jefferson Parish Sheriff Joe Lopinto said a fire on the rig was still burning. Authorities expected the blaze to eventually burn itself out.

Authorities say one person remained missing after the blast and U.S. Coast Guard crews were searching for him.

Lopinto says the search has been complicated by 4 foot to 5-foot (1 meter) seas and stiff winds.

A total of seven people were hurt. Authorities say four of them have been released from hospitals.

7:30 a.m.

U.S. Coast Guard crews hoped to get a helicopter into the air as dawn broke Monday in their ongoing search for a man missing after an oil rig explosion in a lake near New Orleans.

Coast Guard Petty Officer Lexie Preston said that was the plan early Monday morning. She said the helicopter crew also would look to spot any sign of pollution on Lake Pontchartrain, if there is any.

Kenner city officials said authorities at the scene reported that cleaning chemicals ignited on the surface of the oil rig platform, causing the blast Sunday night. At least seven people were injured, five of them critically.

Authorities said Jefferson Parish drinking water will remain safe because it is pulled from the Mississippi River and not the lake.

4:45 a.m.

Rescuers were searching for one person after an oil rig exploded on a lake in Louisiana, injuring seven others.

Jefferson Parish spokesman Antwan Harris said in a news release that reports of fire and smoke being seen from Lake Pontchartrain came into the Emergency Operations center about 7:15 p.m. Sunday.

Chief David Tibbets of the East Bank Consolidated Fire Department says the platform, located in Jefferson Parish, is used for the transfer of oil. He said the department's current goal is to stop oil flow and, if needed, let it burn off safely.